Heritable and life‐style determinants of bone mineral density

Abstract

Familial resemblance in bone mineral density at five skeletal sites was measured among 160 adult members of 40 families. Each family included a postmenopausal mother, one premenopausal daughter, one son, and the children's father. Similarities in selected life‐style factors thought to influence bone density, such as physical activity, smoking, alcohol use, and diet, were also evaluated. Bone density was measured by dual‐energy (total body, femoral neck, and lumbar spine) or single‐photon (radius and os calcis) absorptiometry. Correlation coefficients between the midparent Z score and offspring Z scores of bone mineral density ranged from 0.22 to 0.52 among daughters and from 0.27 to 0.58 among sons. Adjustment of bone density for age, height, weight, and significant life‐style or environmental factors yielded heritability estimates for the five skeletal sites between 0.46 and 0.62. That is, 46–62% of variance in bone density was attributable to heredity. Most estimates derived from the group of daughters were similar to those from the sons. These observations provide support for a significant contribution of heredity to bone density. However, an individual's life‐style may account for a potentially large proportion of the nonheritable variance in bone density.